Processing sensor data from a downhole device

Abstract

A system, a device and a method for processing sensor data generated by a downhole device located in a wellbore. A wavelet transformation is applied to the sensor data to generate a set of filtered data. Data points from the filtered data are removed to yield a reduced dataset. When desired, the original sensor data is reproduced by applying an inverse wavelet transformation to the reduced dataset.

1 . A method for processing sensor data generated by a downhole device, said method comprising: 
 receiving sensor data produced by said downhole device;    generating filtered data by applying a wavelet transformation to at least a portion of said sensor data, wherein said filtered data is comprised of a plurality of data points;    eliminating at least a portion of said plurality of data points from said filtered data to yield a reduced dataset; and    reproducing at least a portion of said sensor data by applying an inverse wavelet transformation to at least a portion of said reduced dataset.    
   
   
       2 . The method of  claim 1 , wherein at least said generating and said eliminating are performed by said downhole device while said downhole device is located in a wellbore.  
   
   
       3 . The method of  claim 1 , further comprising transmitting said reduced dataset via a wireline.  
   
   
       4 . The method of  claim 1 , further comprising storing said reduced dataset in a data store on said downhole device.  
   
   
       5 . The method of  claim 1 , wherein said eliminating removes one or more data points from said filtered data identified as residing above or below one or more predefined thresholds.  
   
   
       6 . The method of  claim 1 , further comprising utilizing the reproduction of said sensor data to generate a log for use in evaluating a bond between a casing and cement placed in an annulus between said casing and a wellbore.  
   
   
       7 . The method of  claim 1 , wherein said eliminating removes at least a portion of said plurality of said data points identified as representing noise.  
   
   
       8 . A system for reducing sensor data generated by a downhole device, said system comprising: 
 a downhole device configured to be positioned in a wellbore, said downhole device comprising: 
 a sensor component configured to produce sensor data;  
 a wavelet transformation component configured to generate filtered data by applying a wavelet transformation to at least a portion of said sensor data, wherein said filtered data is comprised of a plurality of data points; and  
 a data reduction component configured to eliminate at least a portion of said plurality of data points from said filtered data to yield a reduced dataset; and  
   a surface logging device configured to receive said reduced dataset from said downhole device and further configured to reproduce at least a portion of said sensor data by applying an inverse wavelet transformation to at least a portion of said reduced dataset.    
   
   
       9 . The system of  claim 8 , wherein said wavelet transformation utilizes at least one wavelet selected from the Daubechies family of wavelets.  
   
   
       10 . The system of  claim 8 , wherein said downhole device further comprises a digital-to-analog converter configured to convert said sensor data into digitized data.  
   
   
       11 . The system of  claim 8 , wherein said surface logging device is further configured to utilize the reproduced sensor data to create one or more well logs.  
   
   
       12 . The system of  claim 8 , wherein said downhole device further comprises a data store configured to store said reduced dataset.  
   
   
       13 . The system of  claim 8 , further comprising a wireline for connecting said downhole device and said surface logging device, wherein said wireline is configured to carry said reduced dataset from said downhole device to said surface logging device.  
   
   
       14 . A data processing device residing on or within a downhole device and configured to process data while said downhole device is located in a wellbore, said data processing device comprising: 
 a data input component configured to receive sensor data;    a wavelet transformation component configured to generate filtered data by applying a wavelet transformation to at least a portion of said sensor data, wherein said filtered data is comprised of a plurality of data points;    a data reduction component configured to eliminate at least a portion of said plurality of data points from said filtered data to yield a reduced dataset; and    a communication interface configured to communicate said reduced dataset to at least one of a data store residing on or within said downhole device or a surface device via a wireline.    
   
   
       15 . The data processing device of  claim 14 , wherein said sensor data is received from one or more sensor instruments residing on or within said downhole device.  
   
   
       16 . The data processing device of  claim 14 , wherein said data reduction component is configured to eliminate from said filtered data one or more data points identified as residing above or below one or more predefined thresholds.  
   
   
       17 . The data processing device of  claim 14 , wherein said wavelet transformation component is further configured to encrypt said sensor data with an encryption algorithm.  
   
   
       18 . The data processing device of  claim 17 , wherein said encryption algorithm includes said wavelet transformation.  
   
   
       19 . The data processing device of  claim 14 , wherein said data reduction component is configured to eliminate from said filtered data one or more data points identified as representing noise.  
   
   
       20 . The data processing device of  claim 14 , wherein said surface device is configured to reproduce at least a portion of said sensor data by applying an inverse wavelet transformation to at least a portion of said reduced dataset.